This invention relates generally to devices for filtering and separating liquids. More particularly, the present invention relates to filters for filtering fuel or lubricating oil of an internal combustion engine and removing foreign particles and separating water therefrom.
The absence of high standards of quality control in diesel fuel supplies dictates that an effective fuel filter be incorporated into the fuel supply system of a diesel engine. It is not uncommon for diesel fuel to have significant quantities of abrasive particles and water. The abrasive particles present the potential for permanent damage to components of the fuel injection pump. The abrasive particles can also adversely affect the performance of the pump by destroying the ability of the fuel injection pump to precisely meter and deliver fuel at high pressures. The presence of water in the diesel fuel supply can cause corrosion of engine components, and during freezing conditions, can result in interruption of the fuel injection system and/or seizure of moving components. Similarly, water and particulate matter in the lubricating oil must be removed to minimize wear of engine parts.
Commonly, filters employ a disposable filter cartridge which is replaced at pre-established intervals of filter usage. The cartridge is secured to a base that is fixedly mounted to the engine header or some other fixed location.
Some engine designs require a source of low pressure fuel during certain operating events, particularly while starting a cold engine. The low pressure fuel is generally supplied by an injection fuel pump located between the fuel filter and the engine.